Pantographic wall protector and automatic controlling device thereof

ABSTRACT

The invention relates to a pantographic wall protector which prevents the coal face from being crushed and massive chunks of coal from falling onto the face conveyor when, in a long-wall coal mining face, earth pressure is created as a result of the advancing of a coal mining machine; for example, when a drum shearer advances at a speed of approximately 10 meters per minute; and also relates to an automatic controlling device which provides automatic operation of said protector. More particularly, the invention relates to a pantographic wall protector in which a wall protecting plate is either extended toward the wall or folded toward the inner side of the tipping beam of a self-advancing support, by means of a link mechanism and oil-pressure cylinders, and also relates to an automatic controlling device for the pantographic wall protector, wherein a magnet is inserted in a non-movable member, and a lead switch set in the drum shearer which passes over said magnet so that the pantographic wall protector will operate with the advancing of the drum shearer.

United States Patent 1.

Nakajima [4 1 Nov. 19, 1974 PANTOGRAPHIC WALL PROTECTOR AND AUTOMATIC CONTROLLING DEVICE THEREOF [52] US. Cl 299/33, 61/45 D, 299/43 [51] Int. Cl E2ld 23/00 [58] Field of Search 61/45 D, 63; 299/31, 33;

[56] References Cited FOREIGN PATENTS OR APPLICATIONS 1,166,727 4/1964 Germany 61/45 D l,800,846 6/1970. Germany 946,939 H1964 Great Britain 61/45 D Primary Examiner-Dennis L. Taylor Attorney, Agent, or Firm-George B. Oujevolk 57 ABSTRACT The invention relates to a pantographic wall protector which prevents the coal face from being crushed and massive chunks of coal from falling onto the face conveyor when, in a long-wall coal mining face, earth pressure is created as a result of the advancing of a coal mining machine; for example, when a drum shearer advances at a speed ofapproximately 10 meters per minute; and also relates to an automatic controlling device which provides automatic operation of said protector. More particularly, the invention relates to a pantographic wall protector in which a wall protecting plate is either extended toward the wall or folded toward the inner side of the tipping beam of a self-advancing support, by means of a link mechanism and oil-pressure cylinders, and also relates to an automatic controlling device for the pantographic wall protector, wherein a magnet is inserted in a nonmovable member, and a lead switch set in the drum shearer which passes over said magnet so that the pantographic wall protector will operate with the advancing of the drum shearer.

3 Claims, 4 Drawing Figures mm. Om

PATENTEL Raw 1 91914 8.848.828

. SHEEI 30? 4 PATENIE 30V 1 91974 SHEU U-UF 4 w OE PANTOGRAPHIC WALL PROTECTOR AND AUTOMATIC CONTROLLING DEVICE THEREOF BACKGROUND OF THE INVENTION The present invention relates to a pantograph type of I wall protector for use in mining and more particularly to one which operates automatically.

BRIEF REVIEW OF THE PRIOR ART Ordinarily, when a coal mining machine such as a drum shearer advances at a speed of m per minute on a long-wall coal mining face, the coal wall is pressurized and crushed with the rise of earth pressure. This leads to the falling of massive chunks of coal onto the face conveyor.

Since such a situation would impede the advancement of the coal mining machine, it has been'the practice, heretofore, to bring the coal mining machine, etc. to a stop'and to first remove the fallen objects by hand.

The principal object'of the present invention is to provide a pantographic wall protector by which falling of coal onto the face conveyor or self-advancing support would be prevented by means of a wall protecting plate, and by so doing, would ensure the safety of the workers and would prevent damage to the face equipment including ducts.

Another object of the invention is to provide an automatic controlling device for the pantographic wall protector, whereby the link mechanism of the pantographic wall protector will operate homogeneously as the drum shearer advances, and further whereby the drum shearer will be permitted passage when the wall protecting plate of the pantographic wall protector folds toward the inside of the tipping beam of the selfadvancing support, and on completion of passage, the link mechanism will operate automatically to press the coal wall.

Since details of the types and operating mechanisms of drum shearers and self-advancing supports are well known and it is assumed that no importance is attached to such details, drawings and descriptions of the same are omitted.

BRIEF DESCRIPTIONS OF THE DRAWINGS FIG. 1 is a partial cross-sectional perspective view showing the operating state of the pantographic wall protector having a self-advancing support according to the present invention.

FIG. 2 is a perspective view showing automatic control of the pantographic wall protector and drum shearer, with the omission of the self-advancing support and drum shearer sections.

FIG. 3 is a perspective view of the pantographic wall protector of the present invention.

FIG. 4 is another embodiment of the automatic control of the pantographic wall protector and drum shearer, with the omission of the self-advancing support and drum shearer section.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1, 1 is the main body of the machine, on one side of which is provided a double-ranging drum shearer 34 equipped with several rows of picks 119 (see FIG. 4). To permit moving of said drum shearer 34 over the face conveyor, a shoe 25 is fixed to the legs 17 of the main body of the machine I by using pin 24, and said shoe 25 moves as guided by a guide tube as illustrated in FIG. 2. Meanwhile, on the opposite side. a shoe 23 is fixed to the legs 17 on the face side of the drum shearer 34 via a pin 20. A self-advancing support 26 is linked to a shifter fixing bracket 36 of a face conveyor 32 through a shifter 21.

Self-advancing support 26 may be moved by contracting shifter 21 or by extending the same when the face conveyor is moved toward the face side.

A spill plate 16 is fixed to the conveyor so that coal on the conveyor may be prevented from spilling onto the holder of the self-advancing support 26, and at the same time serves as a cable duct to protect the cables of the drum shearer 34. Also. it is designed so that cables 37 will run over the spill plate 16 when drum shearer advance.

Shown at 26 is a self-advancing support (see FIG. 3). Mounted on the center beam 2 of the support are a bracket 19, onto which is fixed an oil-pressure cylinder 4, and a bracket 38 at the tip of said center beam. A bracket 5 is fixed to the tipping beam 3. Shown at 6 are link base plates, to both of which is attached a piston rod 7 via a spacing pin 27 at positions slightly below the middle of said base plates, and link members 8 of identical shape are mounted rotatably at their other ends, which are the free ends.

Shown at 9 is a link supporting member, which has one end mounted rotatably on bracket 5, and immediately beneath this point, an operating link 10 is attached rotatably to the link supporting member. The other end is mounted with an operating link 12 which previously has been fixed to the center of said operating link 10 via a pin 11. One end of said link member 8 is also mounted on the lower part of the link supporting member. I

Shown at 13 is a wall protecting plate. Said operating links 10 and 12 are connected to the back to be rotatable.

An oil-pressure cylinder 14 has one end mounted on link-supporting member 9 via a spacing pin 28 and is rotatable, piston rod 29 which is at the opposite side is connected to spacing pin 11.

In the FIG. 3, numeral 30 designates iron props provided with oil-pressure operating cylinders that are capable of travelling up and down, 31 is an arch frame,

15 a magnet inserted in spill plate 16, 18 a lead switch inserted in the legs 17 of drum shearer l and which should be placed at the approximately same height at which said magnet 15 is located.

In FIG. 2, 32 denotes a face conveyor, 33 denotes a plural number of skids integral construction with face conveyor 32. 35 designates a holder for the self advancing frame which has a width that allows it to be fitted in between said skids 33. Said skids prevent the self-advancing frame from travelling astray sideways, and its also serves as a guide.

The construction of the present invention is as described, when the drum shearer approaches selfadvancing support 26 during cutting of the upper part of the coal face as well as when the lead switch 18 inserted in the shearers legs 17 aligns with magnet 15 inserted in spill plate 16, said lead switch will operate and the piston rod 29 of the oil-pressure cylinder 14 to retreat. This will cause wall protecting plate 13 to contract and contact link supporting member 9.

By contraction and contacting, saidwall protecting plate 13 will make the limit switch (not shown) built in the oil-pressure cylinder 14 to send out a command, whereby the pilot pressure will operate the switching valve (not shown). This, in turn, will cause piston rod 7 of the oil-pressure cylinder torch to retreat, thereby causinglink plate 6, together with wall protecting plate 13, link members 8 and self-advancing support 26 to further fold and contract on the side of center beam 2 and tipping beam 2 of the self-advancing support. This permits the passage of drum shearer 34.

Subsequent to the passage of the drum shearer, the self-advancing support which is to be pressed against the coal face side, is advanced and set. On completion of this, a command will be sent out to the oil-pressure switching valve (not shown) of the oil-pressure operating device, with the result that first and second oilpressure cylinders '29 and 14 and respective links will operate in a sequence reversing that of closing, whereby face protecting plate 13 will be extended and pressed against a new coal face.

As stated above, the upper part of a new coal face will be pressed against by the face protecting plate at all times for the purpose of preventing coal falling. Thus, coal will not fall even though the coal face may be pressurized and crushed by the rise in earth pressure. Furthermore, collapsing of coal into the selfadvancing support due to coal falling will be eliminated and permits speedy movement of the support.

With reference to FIG. 4 which shows another embodiment of the controlling device for the pantographic wall protector, 101 designates the drum shearer proper, whose lateral section on the waste side has a regulating jack 102 mounted via a flange member as well as a piston rod fitted which advance and retreat by means of said regulating jack 102. A sliding element 104 is pivoted to the tip of piston rod 103 to permit said element to advance and retreat freely with said rod 103 and is fitted onto a guide rail 105 installed on the lateral section of said drum shearer proper 101.

A lead switch fixture 107, on one end of which is built a movable member i.e., a semicircular shoe 106 mounted on said sliding element, which, in turn, has a lead switch 108 mounted.

109 designates the shearers legs which support the drum shearer proper 101 which advances and retreats driven by other means, and have a U-shaped grooves formed at their lower end into which one end of shoes 110 and 111 are fitted and fixed by using supporting The semi-cylindrical body at the other end of said shoe 111 is set in'a state to grasp the non-movable member, that is, the tubular guide 114 on top of the support-receiving members 113 which are provided at both ends of face conveyor 112.

The flat concave section 115 which is of an integral construction with said non-movable member, that is, the tubular-guide, and which is formed by hollowing out a section, has a magnet which is shielded all around with a non-magnetic body inserted at a desired position.

The lower part of the sliding surface of shoe 110 which is fitted onto said shearers leg 109 is in contact with the top surface of the support-receiving member 117 located at the other end of said face conveyor 112.

When the lead switch 108 mounted on lead switch fixture 107 comes to a position immediately above the magnet 116 inserted in the flat concave section of tubular guide 114, coordinating with the movement of the drum shearer proper 101 which advances via a tubular guide 114, the lead switch 108 will be operated sending out a command to the oil-pressure operating device and set in the pantographic wall protector and will thereby operate the protector in the same way as descrided for the first embodiment, with the result that the protector will be folded toward the inner side of tip ping beam 3.

It should be understood that the foregoing describes only preferred embodiments of the invention and that the invention is not limited to these embodiments but is intended to cover all modifications and changes which do not constitute departures from the scope of the invention.

What is claimed is:

1. In a mining operation wherein a moveable drum shearer (34) moves against a wall to shear material therefrom, a pantograph wall protector to hold the wall at locations where the drum shearer is not operating comprising in combination:

a. a horizontal shoe (35) with inner and outer ends, the inner end being towards said moveable drum shearer (34);

b. an arch frame (31) extending vertically upwards from said shoe outer end and vertically extending prop means (30) connected to said shoe (35);

c. a center beam (2) with inner and outer ends, said outer end being horizontally supported by said arch frame (31) and said prop means (39) above said shoe and a tipping beam (3) pivotally connected to said center beam and said tipping beam serving to support the ceiling of an excavation;

d. brackets (5) disposed towards said tipping beam inner end, and link bars extending downwards, a horizontally telescoping zig-zag pantograph ex tending from said link bars including a vertical wall protection plate (13) disposed at the outer end of said pantograph, with hydraulic cylinder means connected to said center beam and link bars to extend and contract said pantograph;

e. support means (16) on .said shoe inner end a switch member and an enabling member (15) one of said members being mounted on said support member (16), the other of said member being mounted for motion with said movable drum shearer (34) whereby as the drum shearer (34) advances or re treats, the switch is enabled by said switch enabling means (15) which switch in turn is coupled to and operates said hydraulic cylinder means to expand or contract the pantograph protector so as to allow passage of said drum shearer.

2. A pantograph wall protector as claimed in claim 1 wherein said switch enabling means is a magnet.

3. A pantograph wall protector as claimed in claim 2 wherein said movable drum shearer is affixed to an elongated member sliding horizontally, one of said members being disposed to pass over the other. 

1. In a mining operation wherein a moveable drum shearer (34) moves against a wall to shear material therefrom, a pantograph wall protector to hold the wall at locations where the drum shearer is not operating comprising in combination: a. a horizontal shoe (35) with inner and outer ends, the inner end being towards said moveable drum shearer (34); b. an arch frame (31) extending vertically upwards from said shoe outer end and vertically extending prop means (30) connected to said shoe (35); c. a center beam (2) with inner and outer ends, said outer end being horizontally supported by said arch frame (31) and said prop means (39) above said shoe and a tipping beam (3) pivotally connected to said center beam and said tipping beam serving to support the ceiling of an excavation; d. brackets (5) disposed towards said tipping beam inner end, and link bars extending downwards, a horizontally telescoping zig-zag pantograph extending from said link bars including a vertical wall protection plate (13) disposed at the outer end of said pantograph, with hydraulic cylinder means connected to said center beam and link bars to extend and contract said pantograph; e. support means (16) on said shoe inner end a switch member and an enabling member (15) one of said members being mounted on said support member (16), the other of said member being mounted for motion with said movable drum shearer (34) whereby as the drum shearer (34) advances or retreats, the switch is enabled by said switch enabling means (15) which switch in turn is coupled to and operates said hydraulic cylinder means to expand or contract the pantograph protector so as to allow passage of said drum shearer.
 2. A pantograph wall protector as claimed in claim 1 wherein said switch enabling means is a magnet.
 3. A pantograph wall protector as claimed in claim 2 wherein said movable drum shearer is affixed to an elongated member sliding horizontally, one of said members being disposed to pass over the other. 